Property sheet, ad hoc, property page, flexible data

I am looking for a solution that hopefully someone here has tackled. I want to create "base" tables with fields that are intrinsic to the application. I also want to allow the customers using the application to be able to create their own fields so that they can easily customize the application. These new fields would either be added to the base table or to a separate table with a 1:1 relationship to the base table. The client application will render the controls based on the new fields in a grid to allow a flexible amount of fields to be added by customers.

How would you handle this?

Thanks in advance,

• AC